Function is_permutation_of

include/fplus/container_properties.hpp:608–611

// O(log(n))
template <typename Container>
bool is_permutation_of(const Container& xs, const Container& ys)
{
    return size_of_cont(xs) == size_of_cont(ys) && sort(xs) == sort(ys);
}

// API search type: fill_pigeonholes_to : (Int, [Int]) -> [Int]
// fwd bind count: 1